Circuit interrupter



Nov. 21, 1944.

B. P. BAKER ET AL 2,363,283

CIRCUI? INTERRUPTER Filed Feb. 15, 19 2 WITNESSES: INVENTORS Ben y/771)? PBaker and M Andra? HBQ/M (7% W a BY 2/ a ATTORNE 4 Sheets-Sheet l 21, 1944- B. P. BAKER ET AL 2,363,283

' CIRCUIT IN'IERRUPTER Filed Fe%':-, 18, 1942 Sheets-Sheet. 2

fig 2 [aria/2 WITNESSES: Q w- INVENTORS Benjamin PBaker and Andrew H Be /M1972 Patented Nov. 21, 1944 CIRCUIT IN TERRUPTER Benjamin P. Baker, Turtle Creek, and Andrew H.

Bakken, Edgewood, Pa., assignors to Westinghouse Electric East Pittsburgh, vania & Manufacturing Company, Pa., a corporation of Pennsyl- Application February 18, 1942, Serial N 0. 431,395 7 Claims. c1. zoo-41.4)

The invention relates to circuit interrupters, and more particularly to operating means for high-voltage outdoor circuit interrupters or switches.

Outdoor disconnect switches and high-voltage outdoor circuit interrupters of the type having exposed disconnect contacts must operate satisfactorily under all kinds of weather conditions. In the case of more or less severe ,ice conditions, a very large driving force is necessary to break the contacts loose and start cracking ice which forms on the contacts and othermovable parts. Once the ice is cracked and motion has started a very much reduced force is necessaryto complete the switching operation and to prevent excessive contact speed and stopping difficulties.

An object of the present invention is the provision of an improved operating means for the disconnect contact member of an outdoor switch or circuit interrupter which will satisfactorily operate the contact member under all kinds of weather conditions including severe ice conditions.

Another object of the invention is the provision of a circuit interrupter or switch embodying an improved fluid actuated operating means which is operable to apply a large starting force for initiating the movement of the contact member followed by the application of a reduced force sufiicient to complete the operation of the contact member.

Another object of the invention is the provision of a switch or circuit interrupter embodying an improved fluid actuated operating means comprising two pistons for operating the contact member, one of large diameter for applying a large force to start the motion of the contact member and the other of smaller diameter to maintain speed and complete the operation of the contact member.

Another object of the invention is the provision of a switch or circuit interrupter embodying an improved fluid actuated operating means as described in the preceeding paragraph, wherein the large piston is mounted as a floating piston and moves the regular piston for only a short distance of the initial motion of the regular piston.

Another object of the invention is the provision of an improved high-voltage circuit interrupter having a straight line motion contact member.

Another object of the invention is the provision of a circuit interrupter or switch having a contact member connected directly to a fluid actuated operating piston, and an improved couassigned to the assignee of the pling means for transmitting the motion of the contact member to an auxiliary switch means.

Another object of the invention is the provision of a circuit interrupter or switch having a contact member that is reciprocably movable in a straight line, and an improved coupling means for transmitting the motion to an auxiliary switch means which is adapted to be operated in accordance with the position of the contact member.

Another object of the invention is the provision of a circuit interrupter or switch having a contact member reciprocably operated in a straight line by a fluid actuated operating piston and having a coupling means comprising a twisted member which is caused to rotate by the motion of the piston to transmit the motion to an auxiliary switch means for control or indicating purposes.

The novel features that are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to structure and operation together with additional objects and advantages thereof will be best understood from the following detailed description of one embodiment thereof when read in conjunction with the accompanying drawings, in which:

Figure 1 is a side elevational view, partly in section, of a high-voltage circuit interrupter embodying the features of the invention.

Fig. 2 is a view, partly in section, of the contact operating means and showing the details of construction of the compressed air operating means for the movable disconnect contact member and a portion of the coupling means for transmitting the motion of the contact member to the auxiliary switch means.

Fig. 3 is an enlarged view, partly in section, showing a portion of the control valve means for controlling the operation of the interrupter.

Fig. 4 is a view, partly in section, and taken at right angles to Fig. 3, showing the opening and closing valves, and

Fig. 5 is a view partly in section of the operating cylinder for the movable arcing contact.

The features of the present invention are illustrated as applied to a circuit interrupter of the same general construction as fully disclosed in the copending application of L. R. Ludwig et al., Serial No. 431,394, filed February 18,1942, and

present application.

Referring to the drawings, the reference numeral ll indicates a framework which may be formed of structural steel or other suitable masulators |3, |5 andll is a casing l9 for housing the operating means more clearly shown in Fig. 2. The casing |9 supports a hollow insulator 2| which, in turn, supports a circuit interrupting element 23. A hollow insulator 25 extends upwardly from the element 23 and has a metallic terminal cap 21 secured on its free end. A stationary contact member 29 extends downwardly from the terminal cap 21 into the circuit interrupting element 23. A movable contact member 3| coacts-with the stationary 'contact mem-' ber 29 and extends downwardly through the element 23 and through the hollow insulator 2|. The lower end of the contact member 3| extends into the casing I9 and is connected to a piston or the operating means as'shown in Fig. 2, and which will be more fully described hereinafter.

The contacts 29--3| form arcing contacts of the interrupter and are electrically connected in series with a pair'of disconnect contacts which are arranged to be opened after the arcing contact opens during a circuit opening operation of the circuit interrupter, and closed after the arcing contacts have closed during a closing operation of the circuit interrupter. The discon- 'nect contacts comprisea stationary disconnect contact member 33 mounted in a terminal cap 35 on the upper end of a hollow insulator 31, and a cooperating movable disconnect contact member 39 in the form of a hollow tubular rod which is mounted in bearing means on the easing IQ for straight line movement in the direction of its longitudinal axis, the axis of movement of the contact member 39 being at an angle to the axis of movement of the arcing contact member 3|.

The stationarydisconnect contact member 33 comprises an arm pivotally mounted intermediate its ends by pivot pin'M on a bracket 43 which is secured to a platewithin the terminalcap 35. The left-hand end of the contact arm carries a finger contact assembly 45 having spring pressed fingers adapted to receive and engage the free end of the movable disconnect contact member 39 in the closed position of the movable disconnect contact member. The finger contact assembly 45 is disposed in an opening formed in a, sleet hood 46 on the terminal cap 35. The stationary disconnect contact arm 33 is movable only a very small amount about its pivot 4|, the movement thereof in each direction being limited by stops (not shown). A compression spring 5| is disposed beneath the tail portion of the contact arm 33 for biasing the same in a counterclockwise direction.

The movable arcing contact member 3| and the movable disconnect contact member '39 are electrically connected in series by means of a resilient connector contact means 53 slidably engageable by contact member 3|, nector strips 55. and 51 (Fig. 2). The latter conductor strip 5'! is electrically connected to a similar connector contact means 59 (Fig. 2) that is slidably engageable by the movable disconnect contact member 39.

The hollow insulator 3'! may be supported from the right-hand end of the framework H, and this insulator servesas a housing for transformers and other suitable instruments necessary for the control of the circuit interrupter.

and by con- External circuit connections to the interrupter are made to a terminal 6| carried by the terminal cap 2'! and to a terminal 63 on the terminal cap 35. Thus from the foregoing description, it is apparent that when the circuit interrupter is in closed position, current flows through the interrupter from the terminal 5|, through the terminal cap 21, stationary arcing contact 29, movable arcing contact 3|, connector contact means 53, conducting strips 55 and 5'5, connector contact means 59, movable disconnect contact member 39, stationary disconnect contact member 33 and through a flexible shunt conductor (not shown) to the terminal cap 35 and terminal 63. If the movable arcing contact 3| is operated to open circuit position while the interrupter is carrying a load, an arc will be drawn by the movable arcing contact member 3|. Extinction of arcs drawn by the movable arcing contact member 3| may be accomplished by any suitable arc extinguishing means but preferably by an arc extinguisher of the fluid blast type which, for example, may be of the form fully disclosed in the copending application of L. R. Ludwig and BE. Baker, Serial No. 373,856, filed'January 9. 1941, and assigned to the assignee of this application. Since the present ap plication is not concerned with the arc extinguishing strugture, it is believed that the general designation of the arc extinguishing unit 65 which is supplied with a blastof arc extinguishing fluid such as compressed air will be suffi- .cient for the purpose at hand.

Fluid under pressure, in this instance compressed air, for extinguishing the arc and also for the operating means of the interrupter may be stored in a tank 61 mounted within the framework Extending from the left-hand end of the tank Bl is a'pipe 39 which has mounted thereon and in communication therewith a blast valve mechanism indicated generally at H. The blast valve mechanism has a housing 13 (Fig. 3) which communicates through a short section of pipe 15 with the passage through the interior of the insulator l3. The passage through the insulator l3 communicates through a pipe 11 and through the hollow insulator 2| with the chamber of the circuit interrupting element 23. Thus a blast of air under pressure from the tank Bl is conducted to the are extinguisher 65 by way of the pipe 39, blast valve H, hollow insulator l3, pipe 1'! and tubular insulator 2|. The blast valve mechanism H is of the same construction as that disclosed in the aforementioned copending application of L. R. Ludwig et 211., Serial No. 431,394, and consequently only a very brief description thereof will be given since reference to the aforementioned application of L. R. Ludwig et al. Serial No. 431,394, may be had for details of construction. Briefly, the blast valve mechanism includes a valve 19 in the housing 13 which is biased tov closed position by a spring and which is caused to be opened upon energization of a solenoid 93.

The contact members 3| and 39 are operated member 3| slidably extends through the offset portion of the pipe 11 and through an opening provided therefor in the upper head of the cylinder 99, the lower end of the contact member being connected to the piston IOI. Referring to Fig. 5, the cylinder 99 has a projection I I3formed integral therewith'adjacent the upper end, and this projection has a passage II leading to the upper end of the interior of the cylinder and a port communicating with the passage which is connected by a pipe I I1 the hollow insulator I1.

(Fig. 2) to the passage of This passage of the hollow insulator I1 is, in turn, connected by a pipe II9 (Fig. 4) to an opening valve mechanism for controlling the flow of compressed air to effect an opening operation of the circuit interrupter. The lower end of the operating cylinder 99 is also provided with an integral projection I2I (Fig. 5) having a passage I23 therein communicating with the lower end of the cylinder, and also has a port in communication with the passage which is connected by a pipe I25 (Fig. 2) to the passage through the hollow insulator I5 which conducts air for closing the circuit interrupter. The passage of the hollow insulator I5 Is, in turn, connected by a pipe I21 (Fig. 4) to a closing valve mechanism which will be hereinafter described.

The operating cylinder I03 is mounted in the casing I9 and the upper portion thereof projects outside of the casing I9, through an opening provided in an annular casting or support member I29 which is secured to the wall of the casing I9 by a plurality of bolts I3I. The member I29 serves to support the cylinder I03. The lower end of the operating cylinder I03 fits into a cylinder head I 33 which is secured on this end of the cylinder by a plurality of elongated bolts I35, only one being shown. The bolts I35 pass through a flange of the cylinder head I33 and thread into the annular support member I29. The upper end of the operating cylinder I03 fits into a cylinder head I31 which is secured thereon by a plurality of bolts I39, only one bein shown.

The bolts I39 extend through openings provided in a fiangeof the cylinder head I31 and the lower ends of the bolts thread into the angular support member I29, thus securely clamping the cylinder head on the end of the cylinder. A metallic cover MI" is mounted at the upper end of the cylinder head and is secured thereto by a plurality of bolts I43, only one being shown. The bolts I43 pass through a flange of the cover MI and through the flange of the cylinder head I31. A metallic closure cap I45 is securely clamped over the upper end of the cylinder head I31 by the cover I4I, suitable packing gaskets or other packing material being disposed between the cap I45 and the upper end of the cylinder head I31.

The tubular disconnect contact member 39 extends through bearing openings in the cover HI and end cap I45 into the interior of the cylinder I03, and the lower end of this contact member is connected to the'operating piston I05.

The lower cylinder head I33 of the operating cylinder I03,is provided with passages I49 and I5I- which communicate with the lower end of the interior of the cylinder I03, The compressed air for closing the disconnect contact member is adapted to flow through these passages to the under side of the piston I05. The upper cylinder head I31 is also provided with passages I53 and I55 which communicate with the interior of the cylinder head at the upper end of the cylinder I03 for conducting the flow of compressed air to the upper side of the piston I05 to effect opening operation of the disconnect contact member 39. A sleet hood I51 is provided for before compressed air protecting the exposed portion of the cylinder assembly I03.

Compressed air for operating the pistons IN and I05 to effect opening and closing of the circuit interrupter is derived from the air storage tank 61. For this purpose, the pipe 69 is provided with two branch pipes I59 and I 5| (Fig. 4). The pipe I59 leads to the opening valve mechanism generally indicated at I63, whereas the branch pipe IGI leads to the closing valve mechanism indicated generally at I65. Compressed air from the opening valve mechanism I63 is conducted through the pipe I I9 and passage of the hollow insulator I1 and pipe II1 to the upper end of the operating cylinder 99 above the uppermost position of the operating piston MI. The closing valve mechanism I65 controls the flow of compressed air from the pipe I3I, through the pipe I21, passage of the hollow insulator I5 and pipe I25 to the lower end of the operating cylinder 99 below the lowermost position of the operating piston IM to effect closing operation of the circuit interrupter.

It is important that the disconnect contact member 39 should be opened only after the arcing contact member 3| has been moved to full open position during a circuit opening operation, and it is also desirable that the disconnect contact member 39 should close after the arcing contact member 3I has reached closed position during a closing operation, in order to eliminate the necessity of providing a blast of arc extinguishing fluid for the arcing contact during the closing operation. I order to accomplish this sequence of operation. of the contact members 3| and 39, the operating pistons I 0| and I05 are pneumatically interlocked to insure the desired sequence of operation. For this purpose, the operating cylinder 99 is provide with a projection I69 (Fig. 5) integral therewith adjacent the upper end, and this projection has an air passage I1I formed therein which communicates at one end with the interior of the cylinder at a predetermined point below the upper end of the cylinder. The other end of the passage I1I communicates with a port in the projection I69 which is connected by a pipe I13 (Fig. 2), passage I11 in support member I29, and a pipe I15 to the passages I53 and I55 leading to the upper end of the operating cylinder I03. The point of entry of the passage I1I into the cylinder 99 is so located that it is uncovered by the piston IOI after the piston has moved downwardly a predetermined distance in an opening direction, so that the operating piston IOI will have overcome static friction and come up to nearly full speed is admitted through the pipes I13 and I15 to the upper end of the operating cylinder I03. The construction is such that movable arcing contact member 3I will have reached full open position before the compressed air applied to the upper side of the operating piston I05 starts to move the disconnect contact member 39 to the open position.

A similar projection I19 (Fig. 5) is formed integral with the cylinder 99 adjacent the lower end thereof, and this projection has a passage ISI which communicates at one end with the in-.

terior of the cylinder 99 at a point a predetermined distance above the lower end of the cylinder. The other end of the passage IBI communicates with a port in the projection I19 which is connected by a pipe I83 (Fig. 2) to the passages I49 and I5I of the cylinder head I33, leading to the lower end of the operating cylinder I93. The point of entry of the passage I 8| into the cylinder 99 is arrangedto be uncovered by the operating piston I9I after the piston has moved upwardly a predetermined distance in the closing direction to admit air to the lower end of the operating cylinder I93 beneath the piston I95. The location of the passage I8I is such that the arcing contact member will have been moved to the completely closed position before the compressed air acting on the underside of the operating piston I05 moves the movable disconnect contact member 39 to closed position. I

In order to obtain high speed opening and high speed reclosing of the operation of the circuit interrupter, it is necessary to dump the air in the cylinders ahead of the direction of movement of the operating pistons to atmosphere so as to prevent air ahead of the pistons from retarding the movement thereof. Two dump valves I81 and I91 (Fig. 5) are provided for this purpose. The. dump valve I81 is mounted in the projection I19 at the passage IBI thereof, and this valve has a rod I89 connected thereto, the upper end of which is connected to a piston I9l movable in a cylinder I93 of the projection H3.

The dump valve I81 is biased to closed position by a spring 291, and it is adapted to be operated to open position by the piston I9I immediately upon the flow of compressed air to the upper side of the arcing contact operating piston 'I9I. Opening of the valve I81 opens the lower end of both cylinders 99 and I93 to atmosphere through an atmosphere exhaust port I95, so that the air below the two operating pistons will be at low pressure and will not retard the opening movementof the two pistons. The other dump valve I91 is mounted in the projection I69 of the cylinder 99 and has a rod I99 connected thereto, the lower end of which is connected to a piston 29I mounted in a cylinder 293 of the projection I2I.

The dump valve I91 is biased to closed position by a spring 291 and is adapted to be opened by the piston 29I immediately upon the flow of compressed air to the lower end of the operating cylinder 99 through the passage I23. Opening of the'dump valve I91 connects the upper ends of both cylinders 99 and I93 to atmosphere through an exhaust port 295, thereby causing the air above the operating pistons to be at a low pressure, so that it will not retard the closing movement of the operating pistons.

The opening valve mechanism I63 and the closing valve mechanism I65 are of the same construction'as disclosed in the aforementioned copending application of L. R. Ludwig et al., Serial No.'43l,394, and only a brief description thereof will be given in this application, as the details of construction of the valve mechanisms are not necessary to a complete understanding of the present invention. Referring to Fig. 4, the opening valve mechanism I63 has a Valve 299 which is biased closed and which is caused to be opened by air pressure from the pipe I59 upon energization of a solenoid 2. Similarly, the closing valve mechanism I65 has a valve 2l3 which is biased closed and which is caused to be opened by compressed air from the pipe- I6I upon energization of a solenoid 2I5. The valve mechanisms I63 and I65 are pneumatically interlocked by means of a piston in the valve mechanism I65 and by a pipe 2 I9 connecting the housings of the valve mechanisms I63 and I65 as disclosed in the aforementioned copending application of L. R. Ludwig et al., Serial No. 431,394, so that an opening impulse will always take precedence over'a closing impulse.

The control circuits for controlling the solenoid 93 of the blast valve mechanism 1| and the solenoids 2I I and 2 I 5 of the opening and closing valve mechanisms are the same as disclosed in the aforementioned copending application of L. R. Ludwig et al., Serial No. 431,394, and are not shown in this application as the details thereof are not necessary to a complete understanding of the present invention. It is believed sufficient to state that the solenoid 93 of the blast valve mechanism and the solenoid 2I I of the opening valve mechanism are adapted to be simultaneously energized to efiect opening of their respective valves in response to the operation of an opening relay. The opening relay is caused to be energized in response to the operation of an overload current responsive protective relay or by the closing of a manual opening control switch. The solenoid 93 of the blast valve 1| is caused to be deenergized by auxiliary oontactsof an auxiliary switch means 22I as soon as the disconnect contact member 39 starts its opening movement, consequently the blast valve H is returned to its .closed position. As soon as the opening operation of the circuit interrupter is completedv and the disconnect contact member 39 reaches fullopen position, the opening relay is deenergized by the opening of another pair of auxiliary contacts of the auxiliary switch means 22 I, so that the opening valve returns to closed position. The solenoid 2I5 of the closing valve means is caused to be energized by the operation of a closing relay. The closing relay is, in turn, caused to be operated by either a reclosing relay or by a manual closing control switch. As soon as the closing operation of the circuit interrupter has been completed and the disconnect contact member 39 has reached the fully closed position, the closing relay is deenergized by the opening of a pair of auxiliary contacts of the auxiliary switch means 22 I.

The circuit interrupter is adapted for outdoor application, and consequently must operate satisfactorily under all kinds of weather conditions, including severe ice conditions. In the case of severe ice conditions, a very large driving force is necessary to break the disconnect contacts loose and start cracking the ice from around the sliding contact member 39. Once the ice has been cracked and motion is started, a very reduced force is necessary to prevent excessive contact speed and stopping difiiculties. In accordance with the present invention, a large starting force is applied to the disconnect contact member. 39 for a short distance only of its initial opening movement, by means of an auxiliary floating piston 225 (Fig. 2) which is mounted for sliding movement through a short stroke in the cylinder head I31 of the operating cylinder I93. The piston 225 is of annular construction and is slidably mounted in a short cylinder 221' formed in the cylinder head I31, as shown in Fig. 2. The auxiliary piston 225 is of larger diameter than the main operating piston I95 and is provided with a sleeve 229 which is adapted to receive a reduced cylindrical portion 23I of the main operating piston when the main operating piston is in its uppermost position, as shown in Fig. 2. In the fully closed position of the disconnect contact member 39 both pistons I and 225 are in their uppermost positions as shown. When compressed air is admitted to the upper end of the cylinder I03, through the passages I53 and I55 for effecting an opening operation of the disconnect contact member 39, the compressed air acts on the large surface of the auxiliary piston 225 and moves it downwardly. As the auxiliary piston 225 moves downwardly, it carries with it the main piston I05. The auxiliary piston 225 is moved downwardly only a very short distance, however, when it strikes astop surface provided by a shoulder 235 formed in the cylinder head. At this position the auxiliary piston 225 has opened a bypass passage 231 formed in the cylinder head I31 so as to admit the compressed air around a portion of the side of the auxiliary piston 225 to the upper surface of the main piston I05 at the time the auxiliary piston reaches its stop. This insures that the movement of the main piston I05 will continue at the time the auxiliary piston stops. After the main piston separates from the auxiliary piston, the compressed air then flows through the central opening in the tubular part 229 of the auxiliary piston. The main piston I05 is moved on by the flow of compressed air to the full open position, but at a very much reduced driving force due to the smaller pressure-reactive area of the piston I05. This arrangement provides for a very large starting force to initiate the movement 01 the disconnect contact member followed by the application of a much reduced force sufficient to complete the switching movement. When compressed air is admitted to the lower end of the cylinder I03 for closing the disconnect contact member 39, the piston I05 is moved upwardly to its uppermost position and during the latter portion of this movement carries the auxiliary piston 225 with it to its uppermost position, as shown in Fig. 2, so that the two pistons are ready for the next opening operation. A spring pressed ring 24l of cylindrical cross section is mounted in a ring groove on the main operating piston I05, and this spring pressed ring is adapted to engage in either of two grooves provided at each end of the operating cylinder for retaining the disconnect contact member 39 in open or closed position.

In this circuit interrupter, the operation of the disconnect contact member 39 always follows the operation of the movable arcing contact member 3I. Consequently, ate the auxiliary switch ance with the position of the disconnect contact member 39. In accordance with the present invention, this is accomplished in a simple-and inexpensive manner by means of a twisted square rod 243 which projects into the operating cylinder I03 from the lower end thereof and extends for substantially the full length of the operating cylinder. The lower end of the rod 243 has a reduced cylindrical portion which extends through an opening provided in a bracket 245 secured to the lower end of the cylinder head I33 and has a nut threaded thereon for retaining the rod 243 in mounted position. A crank arm 241 is rigidly secured to the lower portion of the rod 243, and this crank arm 241 has a cylindrical portion 249 which is supported in a journal bearing 25I formed in the cylinder head I33. The rod 243 is thus mounted for rotation in the cylinder I03 about its longitudinal axis it is desirable to oper- 7 means 22I in accordby means of the bearing 25! and the bearing opening in the bracket 245. The twisted square portion of the rod 243 extends through a babbitted opening 253 of corresponding shape formed in the main operating piston I05 and also extends into the hollow portion of the movable disconnect contact member 39. The cylinder I03 has a lining sleeve 252 rigidly secured therein, and this sleeve has a straight slot 254 for receiving a key or guide 256 secured to the operating piston I05 for preventing rotation of the piston as it is moved back and forth in the cylinder. The opening 253 in the piston I05 and the twisted square portion of the rod 243 causes the rod to be rotated about its longitudinal axis by the movement of the operating piston from one end position to the other. The crank arm 241 secured to the rod 243 is utilized to operate the auxiliary switch means 22I which is mounted in the framework II adjacent the lower end of the insulator l3. The auxiliary switch means 22I has an operating arm 255 (Figs. 1 and 3) which is coupled by a rod crank arm 259 is through a portion 251 to a crank arm 259. The fixed to a shaft 26I extending of the hollow pipe member 15.

Also fixed to the shaft 25I interiorly of the hol- The interior low pipe 15 is a crank arm 253. crank arm 263 has pivoted thereto the lower end of a pull rod 265 of insulating material. The rod 265 extends upwardly through the passage in the hollow insulator I3 and into the pipe 11 within the casing I9. The upper end of the rod 265 is pivotally connected to a crank arm 251 (Fig. 2) carried by a shaft 269. A portion of the shaft 269 extends exteriorly of the pipe 11 and has a second crank arm 21I thereon. This last-named crank arm is connected by means of a rod 213 to the crank arm 241 of the twisted member 243. It thus appears that when the crank arm 241 is partially rotated in one direction or the other by the movement of the operating piston I05, the crank arm 21I will be correspondingly rotated transmitting motion by means of the insulating rod 265 and the crank arms 263 and 259 and link 251 to the operating arm 255 of the auxiliary switch means 22 I, thereby operating the auxiliary switch means in accordance with the position of the disconnect contact member 39. The operating mechanism within thehousing I9 is at line potential, whereas the auxiliary switch means is at ground potential upon the framework I I. The auxiliary switch means, however, is insulated from the mechanism within the casing I9 and from line potential by means of the insulating rod 255.

The auxiliary switch means may be of any conventional construction having a plurality of sets of contacts forminga plurality of poles, preferably with each set of contacts being adjustable relative to the operating arm 255 of the auxiliary switch means. Some of the individual sets of contacts or poles of the auxiliary switch means 22I may be utilized in the control circuits for the operating means of the circuit interrupter,

and other poles of the auxiliary switch means may be used to control indicating or signalling circuits.

It is believed that the details of operation of the circuit interrupter will be clearly understood from the foregoing description. The operation of the'circuit breaker is briefly as follows: Assuming the circuit breaker to be in the closed position, opening operation of the circuit breaker is caused to take place upon energization of the solenoid 2 of the opening valve mechanism 'the operating piston opening of the dump valve I81 (Fig. thereby opening the lower ends of both cylinders 99 and I93 to atmosphere, and the compressed air act- I63. Opening ofthe valve, I93 causes the flow of compressed air from the tank 61 through branch pipe I59, opening valve I63, through the hollow insulator I1 and pipe II'I to the upper side of the arcing contact operating piston IOI. The flow of compressed air to the upper side of IOI immediately causes ing on the top of the operating piston IOI moves the same downwardly to open position effecting movement of the arcing contact member 3! to open position. After the operating piston IOI is moved downwardly a predetermined distance,

it uncovers the passage I'll so that compressed air then flows through the passage Ill and pipes 113 and H5 to the upper end of the disconnect contact operating cylinder I03. By the time the arcing contact member 3I reaches full open position, the compressed air acting upon ing piston 225 moves through only a short distance in the downward direction and carries with it the main operating piston I05. By the time the floating piston 225 engages the stop 235, it uncovers the bypass passage 23!, thereby admitting compressed air to the upper surface of the operating piston I05 to continue the downward movement of the main operating piston. As soon as the main operating piston I05 disengages the floating piston 235, the compressed air flows directly through the central opening of the floating piston 225 and drives the main operating piston I05 downwardly to its lowermost position to effect complete opening of the disconnect contact member 39.- The large diameter floating piston 225 applies a large driving force for a short distance of the initial opening movement of the disconnect contact member 39, after which the smaller diameter regular operating piston I05 continues to drive the contact member 39 on to its full open position, but at a much reduced driving force due to its smaller diameter.

During the opening movement of the piston I05, the twisted rod 243 is caused to be rotated in one direction thereby and this motion is transmitted from the crank arm 241 by the previously described linkage to the operating arm 255 of the auxiliary switch means 22 I, thereby causing operation of the auxiliary switch means 22 I.

Since the solenoid 93 of the blast valve II is energized simultaneously with the solenoid 2II of the openingvalve mechanism, the blast valve H is opened to cause a blast of air for extinguishing the arc drawn by the arcing contacts. As soon as the disconnect contact member 39 starts its opening movement the solenoid 93 is deenergized and the blast valve lI closes.

As soon as the disconnect contact member 39 reaches full open position, the solenoid 2II is deenergized and the opening valve I63 thereupon returns to closed position.

A closing or reclosing operation of the circuit interrupter is produced upon energization of the solenoid 2I5 of the closing valve mechanism I65.

The opening of the closing valve I65 causes the flow of compressed air from the tank 61 through the branch pipe IBI, closing valve I65, through the passage of the hollow insulator I5 and pipe I to the lower side of the arcing contact operating piston IIlI; This flow o'f-compressed air immediately opens the dump valve I9 I (Fig. 5), thereby opening the upper ends of both cylinders 99 and I03 to atmosphere. The compressed'air acting on the underside of the operating piston IOI drives the piston to its uppermost position, thereby effecting movement of the arcing contact member 3| to closed position in engagement with the stationary contact 29. As soon as the operating piston IOI is moved a predetermined distance in an upward directio'nyit uncovers the passage I8I, thereby admitting compressed-air from the cylinder 99, through passage I8I and pipe I83 to the lower end of the disconnect contact operating cylinder I03. By the time the arcing contact member SI reaches closed position, the compressed air acting on the underside of the disconnect contact operating piston I05 drives the piston upwardly to its uppermost position, thereby effecting movement of the movable disconnect contact member 39 to closed position. Shortly before the piston I05 reaches its uppermost position it picks up the large diameter floating piston 225 and carries this piston along'with ituntil both pistons reach their uppermost end positions.

The'upward or closing movement of the disconnect contact operating piston I05 causes rotation of the twisted rod 243 in a direction opposite to that produced by the opening movement of the piston. This movement of the twisted rod 243 is transmitted by the crank 241 and previously described insulating linkage to the operating arm 255 of the auxiliary switch means 221,

thereby operating the auxiliary switch means to a position corresponding to that of the closed position of the disconnect contact 39.

Just before the disconnect contact member 39 reaches the fully closed position, the solenoid 2I I is deenergized and the closing valve I returned to closed position.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details and arrangement of parts thereof may be made without departing from some of the essential features of the invention. It is desired, therefore, that the language of the appended claims be given the broadest reasonable interpretation permissible in the-light of the prior art.

We claimflas our invention: 1. A circuit interrupter comprising a pair of arcing contacts separable to provide a current interrupting break, a pair of external air break disconnect contacts connected in series therewith,

compressed air operating means for said contacts including a cylinder and a piston therein for actuating said arcing contacts, another cylinder and a piston therein for actuating the movable disconnect contact to open and to closed circuit positions, a source of compressed air for operating said pistons, control valve means for controlling the flow of compressed air to said cylin ders, means for causing said pistons to be operated in a" predetermined sequence during an "opening operation to first open said arcing contacts and then open said disconnect contacts, an additional piston means in said disconnect contact operating cylinder adjacent one end thereof, said additional piston means being of larger diameter than said disconnect contact operating piston and being movable through a short stroke by the flowof compressed air to said end of the cylinder to apply a large starting force to said disconnect contact member for a short distance of the initial portion of the opening stroke of said contact member.

2. A circuit interrupter comprising a pair of arcing contacts separable to provide a current interrupting break, a pair of external air break disconnect contacts connected in series therewith one of which is rcciprocably movable in a substantially straight line to open and closed positions, fluid actuated operating means for said pairs of contacts, means controlling said operating means to cause said operating means to first open said arcing contacts and then open said disconnect contacts during an opening operation, a member rotatable'about an axis extending in the direction of th axis of movement of said movable disconnect contact and movable about its rotatable axis by the movement of said disconnect contact, an auxiliary switch means, and means connecting said auxiliary switch means to said rotatable member for operation thereby.

3. A circuit interrupter comprising a pair of arcing contacts separable to provide a, current interrupting break, a pair of disconnect contacts connected in series therewith one of which is reciprocably movable in a substantially straight line to open and closed positions, compressed air operating means for said pairs of contacts including a cylinder andypiston therein for actuating said arcing contacts and another cylinder and piston therein connected to the movable disconnect contact for actuating the same, means for causing said pistons to be operated in. a predetermined sequence to first open said arcing contacts and then open said disconnect contacts during a opening operation and to close said disconnect contacts after said arcing contacts are closed during a closing operation, a member extending into said disconnect contact operating cylinder in the direction of the longitudinal axis of said cylinder, said member being mounted for rotation about an axis extending in the direction of the axis of movement of said disconnect contact operating piston and being movable about its axis by the movement of said piston, an auxiliary switch means, and means connecting said auxiliary switch means to said rotatable member for operation thereby.

4. A circuit interrupter having a reciprocable contact member movable in a substantially straight line to open and closed positions, fluid actuated operating means therefor comprising a cylinder, a piston in said cylinder rigidly connected to said contact member for moving said contact member from one of said positions to the other, a rod extending into said cylinder and v thereby.

5. A circuit interrupter having a reciprocable contact member movable in a substantially straight line to open and closed positions, fluid actuated operating means therefor comprising a cylinder, a piston in said cylinder rigidly connected to said contact member for moving said contact member from one of said positions to the other, a rod extending into said cylinder in the direction of the longitudinal axis of the cylinder, said rod being mounted for rotation about its longitudinal axis, means coupling said rod to said piston for causing said rod to be rotated by the movement of said piston, an auxiliary switch means, and means connecting said switch means to said rod for operation thereby.

6. A circuit interrupter comprising a reciprocable contact member movable in a substantially straight line to open and closed positions, operating means for moving said contact member to open and closed positions, a member rotatable about an axis extending in the direction of the axis of movement of said contact member and movable about said axis by the movement of said contact member, an auxiliary switch means, and means connecting said rotatable member to said auxiliary switch means for operating said auxiliary switch means by said rotatable member.

7. In a high voltage circuit interrupter having a contact member movable to open and to closed circuit positions through a relatively long stroke, fluid actuated operating mean therefor comprising a cylinder and a piston in said cylinder connected to said movable contact member, auxiliary switch means for said circuit interrupter operated in accordance with the motion and position of said contact member, said auxiliary switch means having a short stroke as compared to the long stroke of the contact member, and means for operating said auxiliary switch means by and in accordance with the motion of said piston at a reduced motion relative to the motion of said piston, said last-mentioned means including a rotatable element in said cylinder rotated by the motion of said piston and motion transmitting connections between said rotatable element and said auxiliary switch means.

BENJAMIN P. BAKER.

ANDREW H. BAKKEN. 

